Nutrition and Exercise Science

Nutrition Overview

Senior Seminar in Exercise Science

Instructor: Garcia

Outline

  • Scope of Practice
  • Macronutrients
  • Micronutrients
  • Fluids
  • Food Labels
  • My Plate
  • Special Dietary Considerations
  • Obesity and Weight Management
  • Ergogenic Aids
  • Eating Disorders

Scope of Practice

  • Nonmedical Nutrition Information: Allowed to provide nonmedical nutrition information using established nutrition guidelines if the guidance is accurate and directed towards healthy individuals.
    • Principles of Healthy Food Preparation: Cooking methods, e.g. frying vs. baking, differences in cooking oils.
    • Essential Nutrients: Knowledge of recommended amounts based on Dietary Reference Intakes.
    • Effects of Nutrient Deficiencies/Excesses: Understand the consequences of inadequate or excessive intake of nutrients.
    • Sources of Essential Nutrients: Specific foods or supplements that provide essential nutrients.
    • Food Guidance Systems: How to read food labels and interpret concepts like MyPlate.
    • Basic Functions of Nutrients:
    • Carbohydrates (CHO)
    • Proteins
    • Fats
    • Vitamins and minerals
    • Water
    • Nutritional Impacts on Chronic Diseases: The relationships between chronic diseases and nutrient excesses/deficiencies.
    • Hydration Guidelines: Recommendations for maintaining proper hydration.

Important Terms

  • Recommended Dietary Allowance (RDA): The average daily nutrient requirement adequate for meeting the needs of most healthy people within each life stage/sex.
  • Adequate Intake (AI): The average daily nutrient intake level recommended when RDA cannot be established.

Bioenergetics and Metabolism

  • Bioenergetics: The flow of energy in biological systems; the conversion of macronutrients into biologically usable forms of energy.
  • Metabolism: The total of all catabolic and anabolic reactions in a biological system.
    • Catabolism: Breakdown of larger molecules into smaller molecules, associated with the release of energy.
    • Anabolism: Synthesis of larger molecules from smaller molecules, accomplished using energy released from catabolic reactions.

Macronutrients

  • Macronutrient Overview
    • Carbohydrates (CHO): 4 kcal/g
    • Acceptable Macronutrient Distribution Range (AMDR): 45-65% of total kcal.
    • Functions in the Body:
      • Preferred energy source for aerobic and anaerobic activities.
      • Protein sparing (helps preserve protein for a more critical use).
      • Plays a role in lipid metabolism.
      • Provides energy storage.
Types of Carbohydrates
  • Monosaccharides: Simple sugars such as:
    • Glucose
    • Fructose
    • Galactose
  • Disaccharides: Composed of two monosaccharides:
    • Lactose
    • Sucrose
    • Maltose
  • Polysaccharides: Complex carbohydrates:
    • Starch
    • Fiber
    • Glycogen
Glycemic Index and Glycemic Load
  • Glycemic Index (GI): Ranks carbohydrates based on how quickly they raise blood glucose levels. Measurements based on consuming 50g of specific carbohydrates.
    • Reference food: Glucose or white bread (GI = 100).
    • GI Classifications:
    • Low GI: 55 or less (e.g. apples, bananas).
    • Medium GI: 56-69 (e.g. brown rice, sweet potato).
    • High GI: 70+ (e.g. cornflakes, watermelon).
  • Glycemic Load: Assesses the impact of carbohydrate food on blood sugar considering standard serving sizes.
CHO and Performance
  • Endurance Athletes: Require 8-10 g CHO/kg body weight for performance, especially training 90 minutes or more per day at moderate intensity.
  • Strength and Sprint Athletes: Require 5-10 g CHO/kg body weight.
  • Daily Recommended Intake (DRI): Fiber intake should be 21 to 29 g/day for women and 30 to 38 g/day for men.

Protein

  • Protein Overview: 4 kcal/g
    • The only macronutrient containing nitrogen.
    • AMDR: 10-35% of total kcal.
  • Roles of Protein:
    • Enzyme and protein synthesis.
    • Transportation of nutrients.
    • Hormone production.
    • Maintaining fluid and acid-base balance.
    • Supporting growth and tissue maintenance.
    • Serves as an energy source when needed.
Types of Protein
  • Essential vs. Conditionally Essential vs. Nonessential Amino Acids:
    • Essential Amino Acids: Cannot be synthesized by the body and must be obtained through diet.
    • Conditionally Essential Amino Acids: Normally nonessential but can become essential under certain circumstances (e.g., illness).
    • Nonessential Amino Acids: Can be synthesized by the body.
Quality of Protein
  • Protein Digestibility-Corrected Amino Acid Score (PDCAAS):
    • A measure of protein quality based on amino acid requirements and digestibility.
    • A score of 1.0 indicates the protein exceeds essential amino acid requirements.
    • Examples:
    • Beef, poultry, fish: 0.8-0.92
    • Soy, egg, milk proteins: 1.0.
Protein Requirements for Athletes
  • General Recommendation: 0.8 g protein/kg body weight for general population.
    • Aerobic Endurance Athletes: 1.0-1.6 g/kg body weight.
    • Strength Athletes: 1.4-1.7 g/kg body weight.
  • Combined Strength and Aerobic Athletes: 1.4-1.7 g/kg body weight.

Fats

  • Overview of Fats: Lipid is a broader term including triglycerides, phospholipids, and sterols; providing 9 kcals/g.
    • AMDR: 20-30% of total kcal.
  • Functions in the Body:
    • Energy source and storage.
    • Insulation and protection.
    • Regulation and signaling.
    • Aiding digestion.
Types of Fats
  • Saturated vs. Unsaturated Fats: Understanding their impact on health.
    • Saturated Fats: Primarily of animal origin with a strong link to heart disease (e.g., red meat, butter).
    • Unsaturated Fats: Considered healthier, primarily from plants (e.g., olive oil).
    • Trans Fats: Result of hydrogenation, harmful and linked to cardiovascular diseases.
  • Cholesterol: A waxy substance found in animal tissues; used to assess heart disease risk.
  • Omega-3 Fatty Acids: Special type of polyunsaturated fat beneficial for heart health found in cold water fish.
Lipoproteins in Fats
  • Types of Lipoproteins: Particles that carry cholesterol in the blood:
    • Very Low-Density Lipoproteins (VLDL)
    • Low-Density Lipoproteins (LDL)
    • High-Density Lipoproteins (HDL)
Impacts of Fats on Health
  • Risk Factors: High cholesterol and triglycerides increase heart disease risk.
  • High intakes of saturated and trans fats also correlate with increased LDL.
  • High levels of HDL are considered protective against heart disease.

Micronutrients

  • Vitamins: Organic substances needed in small amounts for specific metabolic functions.
    • Water Soluble Vitamins:
    • Vitamin B1 (Thiamin)
    • Vitamin B2 (Riboflavin)
    • Vitamin B3 (Niacin)
    • Vitamin B6 (Pyridoxine)
    • Folate (Vitamin B9)
    • Vitamin B12
    • Vitamin C
    • Fat Soluble Vitamins:
    • Vitamins A, D, E, K
Functions/Benefits of Key Vitamins
  • Vitamin A: Essential for healthy vision, skin, bones, and reproduction.
  • B Vitamins: Help in energy metabolism and nervous system health; critical for cell creation and DNA synthesis.
  • Vitamin C: Acts as an antioxidant, improving immune function and aiding in iron absorption.
  • Vitamin D: Important for calcium absorption and bone health.
Minerals
  • Major Minerals: Needed in larger amounts (e.g., calcium, potassium).
  • Trace Minerals: Needed in small amounts (e.g., iron, zinc).
Functions/Benefits of Key Minerals
  • Calcium: Key for building bones and teeth; assists in muscle and heart function.
  • Iron: Vital for oxygen transport in red blood cells and energy metabolism.
Micronutrient Intake
  • Guidelines: Eat a wide variety of foods to ensure all micronutrient needs are met; incorporate plenty of fruits and vegetables (i.e., eat the rainbow).

Fluids

Importance of Water

  • Water: Largest percentage of body volume; crucial for hydration.
    • Euhydration: State where body water levels meet demands; vital for optimal functioning.
  • Roles of Water in the Body:
    • Transportation of nutrients and waste.
    • Medium for biochemical reactions.
    • Lubrication for joints and tissues.
    • Temperature regulation.
  • Daily Water Loss: Approximately 2.5 L/day through sweat, urine, and feces.
  • Recommended Water Intake:
    • Adult males: 3.7 L/day
    • Adult females: 2.7 L/day
Body Water Composition
  • 40% Total Body Water distribution:
    • 66% intracellular fluid (fluids inside cells)
    • 33% extracellular fluid (including interstitial fluid and blood plasma)
Electrolytes
  • Electrolytes: Charged ions such as sodium, potassium, and chloride; essential for maintaining water balance and proper cell function.
Hydration and Exercise
  • Dehydration: Occurs when there is a loss of >2% body weight; primarily caused by inadequate fluid intake and excessive sweat loss.
  • Hyponatremia: Low sodium levels in blood, often due to overconsumption of hypotonic fluids during excessive sweating.
Hydration Guidelines During Exercise
  • Recommendations:
    • Prehydrate several hours before exercise.
    • Children: 5 oz cold water every 20 min.
    • Adolescents: 9 oz cold water every 20 min.
    • Adults: Individual hydration programs; consume sports drinks in prolonged activities with specified electrolytes and carbohydrates.

Alcohol

  • Caloric Energy: 7 kcal/g; considered a psychoactive drug.
  • Typical Alcohol Content:
    • Beer: ~150 kcal
    • Wine: ~80 kcal
    • Liquor: ~65 kcal
  • Surgeon General Advisory: Alcohol consumption is linked to increased cancer risk and is the third leading preventable cause of cancer in the U.S.

Case Studies

  1. Football Lineman: 18-year-old seeks to increase lean body mass; dietary modifications required due to inadequate progress despite appropriate training.
  2. Swimmer: Weighing concerns post-practice; requires evaluation of hydration, diet, and potential health issues due to weight fluctuations.
  3. Education Session on Healthy Fats: Focus on key dietary differences in fats for college students attending health seminars.

Food Labels

Reading Food Labels

  • Nutrition Facts:
    • Serving Size
    • Calories: Included total and from fat.
  • Daily Values: Percentages for limiting and important nutrients (e.g., fats, sugars, vitamins).
  • Changes Post-2016: Updated serving sizes and altered presentation for clarity.
Important Terms
  • Free: Less than 5 calories per serving.
  • Low: 3g or less fat; low sodium: 140mg or less.
  • Lean/Extra Lean: Implications for fat content.
  • Reduced: At least 25% less of a given nutrient.

MyPlate

  • USDA Nutritional Guide: Visual depiction of healthy eating.
    • ½ plate fruits and vegetables, ¼ grains, ¼ protein; emphasizes low-fat dairy options.
  • Pros and Cons:
    • Easier to visualize but lacks details about fat and water guidance.

Special Dietary Considerations

Target Groups

  • Children: Focus on variety within fruits and vegetables; limit sugar.
  • Older Adults: Emphasize protein intake, hydration, B12, and sodium limits.
  • Pregnant People: Needs for folic acid, iron, omega-3 fatty acids, vitamins B & C.

Obesity and Weight Management

Body Mass Index (BMI)

  • Utilizes height and weight as an indicator of potential weight issues.
    • Not diagnostic; classifications for underweight, normal, overweight, and obesity.
  • Waist Circumference: Assesses risk associated with fat distribution (men >40 in; women >35 in).
Health Risks
  • Underweight Risks: Include malnutrition, osteoporosis, and lowered immunity.
  • Overweight/Obesity Risks: Linked to heart disease, hypertension, and other health issues.
Energy Balance Equation
  • Energy In: All food/beverage intake.
  • Energy Out: Includes BMR/RMR, thermic effect of food, and physical activity.
Limitations of Energy Balance
  • Difficulty in accurately assessing dynamic variables affecting weight management.

Weight Management Strategies

  • Behavioral Modifications: Focus on lifestyle changes through clients' interactions.

Ergogenic Aids

  • Performance Enhancing Substances: Understanding the effects and risks, including:
    • Anabolic Steroids: Synthetic testosterone derivatives, stimulate muscle growth at a risk of serious side effects.
    • Human Growth Hormone: Involves growth stimulation with unclear efficacy for athletes.
    • Erythropoietin (EPO): Increases red blood cell production but raises risk for blood-related complications.

Dietary Supplements

  • Common Supplements and Efficacy:
    • Arginine: Claims related to nitrogen production but not substantiated by research.
    • L-Carnitine: Aims to enhance fat oxidation and recovery; efficacy is not clear.
    • Creatine: Increases muscle creatine stores leading to strength gains.
    • Caffeine: Known ergogenic effects when consumed appropriately.
Drinks and Caffeine Content
  • Comparisons of caffeine content across popular beverages for awareness.

Disordered Eating

Disorders Defined

  1. Anorexia Nervosa: Characterized by severe weight restriction and distorted body image.
    • Symptoms include low blood pressure, brittle hair, and lethargy.
  2. Binge Eating Disorder: Involves repeated episodes of uncontrolled eating.
    • Associated with feelings of guilt and discomfort.
  3. Bulimia Nervosa: Characterized by binge eating followed by purging behaviors.
    • Symptoms include sore throat, swollen glands, and severe dehydration.
  4. Orthorexia Nervosa: Obsession with eating “healthy” foods leading to restrictive behaviors.
Prevention Strategies
  • Take warning signs seriously; provide accurate nutrition information; and de-emphasize weight focus.
Female Athlete Triad
  • Interdependence of disordered eating, cessation of menstruation, and osteoporosis.
Relative Energy Deficiency in Sports (RED-S)
  • Definition of the syndrome and implications for health and performance in athletes.